USING ADVANCED PTC WITH MOVING BLOCKS TO IMPROVE THE OPERATIONAL FEASIBILITY OF SHORT TRAINS ON SINGLE-TRACK RAIL CORRIDORS

摘要

Rail transportation can achieve excellent economies of scale related to labor, fuel, infrastructure, and equipment. To magnify these inherent efficiencies, many U.S. Class I railroads have traditionally focused on increasing average train lengths. However, railroads may soon leverage investments in Positive Train Control (PTC) communications network infrastructure to implement "advanced PTC" systems with moving blocks. Advanced PTC could also enable single-person crews or driverless trains, reducing the labor incentive for long trains. Compared to long trains, shorter trains can facilitate more direct trains that bypass intermediate classification yards and/or more frequent train departures between origin-destination pairs, expediting the movement of railcars and yielding potentially significant time and cost savings. Conversely, operating the same number of railcars in shorter trains increases the total number of trains traversing a given rail line, increasing congestion and delay. To investigate the effects of a short-train operating strategy on rail corridor performance, Rail Traffic Controller software is used to simulate varying combinations of long and short trains operating on representative single-track rail corridors under fixed or moving block control systems. Comparing delay performance reveals that, for a fixed traffic demand, increases in delay are likely when converting existing long trains into more frequent shorter trains. However, moving blocks can be used to partially mitigate these performance impacts. Considering the ability of shorter trains to reduce yard and terminal dwell time, advanced PTC with moving blocks can improve the overall net benefits of shorter trains, enabling faster railcar transit times and higher quality service for shippers.